A new type of distal myopathy in two brothers.

Two brothers are described with a distal myopathy different from the known hereditary distal myopathies. Early adult onset, beginning in the distal leg muscles with marked elevation of creatine kinase (CK) activity (20 to 30-fold) were the characteristic features. The parents of the patients had no symptoms or signs of myopathy. Their serum CK-activity was in the normal range. There was parental consanguinity, so the distal myopathy in these brothers is probably an autosomal recessive inheritance.